Streetside Swales and Enhanced Tree Pits

Currently, DEP has constructed five enhanced tree pits and six streetside infiltration swales to evaluate the performance, maintenance requirements and total costs of green infrastructure in the city’s right-of-way. The design of each installation involves a large green space in the sidewalk with two curb cuts: one to channel runoff from the street into the installation and the other to allow ponded stormwater or overflow to travel back to the street for conveyance to storm sewer catch basins. Specifications for the curb cut and attached plate, while developed specifically for DEP’s pilots, were reviewed and approved by DOT, DDC and DEP and are readily available for future green infrastructure applications in the right-of-way.

The enhanced tree pits were constructed with additional subsurface storage technologies; as a result, stormwater would be stored for an extended period of time to allow for infiltration and provide a reservoir of water for the trees. Each of these pilots will be monitored for a period of three years.